Relief device for oil tanks



Dec, 9, 1924.

` J. E. CREWS RELIEF DEVICE FR on. TANKS Filed March 25, 192s Joh 11 E Crews {lune/wko@ m Il 5 MH k\^\` rasata Dec. e, 1924.

srATES JOHN EDWARD GIB-EWS, OF SUNLAND, CALIIIEOB'NIA,v ASSIGNOB TO DAVID F. YOUNG Y BLOODOF SAN ANTONIO, TEXAS.

RELIEF DEVICE' ron on. ranks.

Application tiled. March 28, 1923. Serial No. 627,192.

To all whom 'it may concern.' e Be it known that I, JOHN E. Crews, a c1t1- zenof the United States, residing at Sunland, in the county of Los vAngeles and State of California, have invented new and useful lmprovements in Relief Devices for )il Tanks, of which the following is a specifil cation.

which illustrates the My invention relates to an automatic relief device adapted to be installed upon the decks of tanks which are usedfor receiving and storing petroleum or derivatives of petroleum such as gasoline, kerosene, distillate or other volatile liquid.

'lhe general object of the invention is to provide a device which normally7 forms a liquid seal for preventing the escape and dissipation of the volatile'contents of the liquid contained in the tank, but which is provided with means for relieving excess pressure or vacuum when the same becomes great enough to threaten injury tothe tank. The invention is also provided with means for adjusting the amount of pressure which may be reached within the tank beforel a'ording relief, whereby the device may be adapted to suit the strength of the tank to which it isto be applied. The sealing device also is lled automatically when a certain level` is :reached within the tank, and after the device is once installed, no further attention is required. 'lhe invention will be best understood from the following description considered in connection with Ythe accompanying drawing preferred structure by means of which the invention may be carried out.. l

ln the drawings lFig. 1 is a vertical sectional view of a portion of a tank having my device installed thereon.

Fig. 2 is a similar view showing the liquid seal and pressure-releasingn device in section. Fig. 3 1 s a sectional view on the line 3 3 of Fig. l.` l y Fig. a is a sectional view on the line -l4 of Fifg. 1. p

Re erring more specifically to the drawing, ,the tank 5, which is'adapted to contain oil or other volatile liquid, is provided, as usual, with a top wall or deck 6 on which the invention is mounted. Thel invention comprises a U-shaped pi 7 having legs Sand 9 secured to the under sideoff the deck 6, by flanged` overow of the couplings 10 and 11 or other suitable means, the lower part ofthe pipe being adapted to contain sealin liquid 12 of the same character as the llquid contained in the tank. One leg, as 9, is provided with a series of internally threaded openings arranged one above the other, to one of which may be onnected a nipple 13 and elbow 14 from which a comparatively small tube 15 extends downwardly to a point near the bottom of the tank, preferably about eighteen inches from the bottom. '.lhe other openings may Vbe provided with plugs 16, either one of which may at an time be removed to adjust the tube 15 andnipple 13.

It will be understod that the tube 15 provides restricted means of communication be-v may also be discharged from the tank into the pipe 7, whenever the level within the tank rises to a sucient height. Thus, after the device is once installed, it ordinarily requires no further attention. 'llhe leg 9 opens into a return bend 26 forming a co tmuation of the `pipe and providing a free communication between the'same and the .upper portion of the tank. Whenever 'the gases escaping from the liquid in the tank.

create a pressure, the liquid 12 is forced downwardly in the leg 9, and if the pressure ben comes greater than the predetermined maximum, a portion of the gas is permitted to escape through the liquid seal and leg 8 into Ythe atmosphere. 'A dome 17 is secured -to the upper surface of the deck 6 to receive any liquid 12 which may be caused by the pressure in thel leg 9, the dome being provided with a port 18 through which the gases mayv escape until the pressure within the tank is relieved.

Whenever oil is pumped out of the tank, thus tending to create a vacuum, as soon as the deficiency in pressure within'the tank reaches a point liable to cause injury to the tank, the pressure of the atmosphereI enter` ing through the port 18 will cause the oil- 12 to rise in the leg-9l until the leg 8 is emptied and the atmosphere may outer .through the pipe 7 and returnY bend 26 and relieve the vacuum condition. f

' The tube 15 provides a compensating device through which to-gage the amount of pressure or vacuum which may be reached before being relieved. The connection between the tube 15 and the leg 9 may be adjusted vertically by interchanging the same with one of the plugs 16. Thus, when the tube is connected with the lowermost hole, the maximum pressure or vacuum'may be four ounces to 'the square inch, and when connected to one of the other openings, the maximum pressure or vacuum may be eight ounces or sixteen ounces to the square inch, respectively. It will, of course, be understood, that the height of these openings above the horizontal portion of the pipe 7 will determine the amount of pressure to which the relief device is responsive and may be 4 varied, as desired, and the tube 15 may be connected to any one of the openings to which the strength of the tank is adapted. 20 j The return bend 26 and dome 17, therefore, provide means for relieving excess vacuum or pressure within the tank, and at the same time retain suliicient liquid to restore the seal as soon as the abnormal con dition is corrected. The tube`15 also provides means for regulating the pressure by permitting any excess oil to escape from the tube 7 andalso permitting the tube to be automatically re-iilled? A clean-out plug .19 is preferably rovided in the bottom of the pi e 7, so t at if the device becomes clogge by sediment of any kind, it may be immediately relieved by removing the plug and cleaning out the pipe.

While I have shown and described specifically. one form in which my invention may be embodied, it will be understoodl that this is merely illustrative and that the details of construction may be modified, and that the seal `may be' located in various positions either inside or outside the tank, without departing1 from the scope of the invention as 1 claime l1. A receptacle for liquids comprising top, p bottom and side walls, a pipe secured to the `top' wall and having a y/sulzistantially U- shaped portion .depending therefrom and adapted to contain liquid to form aseal, one end of the pipe being open to the atmosphere and the other end open to the interior of the receptacle,and a comparatively small r.tube communicating with the interior of one I 5 branch of -the pi'pe below the end ,which is open to the interior of the Vreceptacle and extending downwardly therefrom toward the .bottom of the receptacle.

"liquid-to form a seal """tap ed`intoione leg of y 2. A receptacle for liquids, comprising top, bottom andy side walls,

U-shaped pipe secured tothe to wall and depending therefrom and adapte to contain a plurality of holes the pipe at diferent leve s, a comparatively small.v tube adapted Ato be secured in any one of said holesand a substantially top, bottom and side walls, a substantially U- haped pipe with each end secured to and opening through the top wall and depending therefrom, a return bend forming a continuation of one leg of the pipe and opening into the top of the receptacle, a comparatively small tube communicating with theinterior of one legof the pipe and extending downwardly toward the bottom of the receptacle.

4.' A .receptacle for liquids, comprising top, bottom and side walls, a substantially U-shaped pipe secured to the top wall and depending therefrom, a return bend forming a continuation of one leg of the pipe and opening into the top of the receptacle, one of said legs having a plurality ofl openings therein, a comparatively small tube selectively connected to one of said openings and extending to a `point near the bottom of the tank, and plugs for closing/,the remaining openings. i

5. A receptacle for'liquids, comprising top, bottomV and side walls, a substantially U- haped pipe secured to the top wall and depending therefrom and adapted to contain form a-seal, and means for adlmiting the height of said liquid, amount of pressure vunder liquid to justably so as to adjust the which the seal will be broken. V

6.- A receptacle for liquids comprising top, bottom andsde walls, a substantially U-shaped pipe secured to the top wall and depending therefrom and adapted to contain liquid to form a seal, means above the top .wall to retain the overflow from one leg of e, and means below the end of the the pi eg for automatically, filling the seal other with liquidpfrom the rebe tacle when the l latter reaches a predetermmed height.

7. The combination with a receptacle for liquids, of a substantially U-shaped pipe de pending within the receptacle and having each leg secured to an opening through the wall of the upper part of the receptacle, onel communicating with the atmosphereand the other continuing 1n a return bend which opens into the receptacle, and means y'for "automatically introducing a portion of the liquid Vcontents of the receptacle into the lower part of the U-shaped pipe to'form a liquid seal when said liquid contents reaches a predetermined level below the top v of the receptacle. l

8, A li uid seal for receptacles containing li ui s, comprising a substantially U- sha e pipe adapted to be secured to the un er side of the tcp vwall ofthe receptacle, adjustable means fo'r establishing direct communication between one leg of the pipe and the bottom part ,ofthe receptacle, a return bend forming a continuation of one leg of the pipe and adapted to communicate with the interior of the receptacle to permit relief of ressure therein, and an overflow receptac e connected with the other leg of the plpe.

9. A. liquid seal for receptacles containing liquids, comprising a substantially U-shaped pipe adapted to be secured to the underside of the top wall of the receptacle, a return bend forming a continuation of one leg of the pipe and adapted to communicate with the interior of the receptacle to permit relief of ressure therein, and an overflow receptac e connected with the other leg of the pipe and open to the atmosphere.

10. A liquid seal for receptacles, comprising a substantially U-shaped pipe adapted to be secured to the underside of the top Y Wall of the receptacle, and adjustable means for establishing direct communication between one leg of the pipe and the bottom part of the receptacle.

11. A receptacle for liquids comprising top, bottom and side Walls, a substantially Ushaped pipe secured to the top Wall and depending therefrom, one leg of the pipe opening to the atmosphere, and a return bend forming a continuation of the other leg of the pipe and opening into the top of the receptacle.

12. In combination with a receptacle for liquids, a pi e adapted to contain liquid to form a liqui seal for the receptacle, one end ofthe pipe being open to the atmosphere and the other end open to the interior of the receptacle, and means for automatically introducing liquid into the pipe to form a seal when a certain level is reached Within the receptacle, which level is belo-W the end which is open to' the interior of the receptacle.

13. A liquid seal for receptacles containing liquids, comprising means responsive to a predetermined excess of pressure inside the receptacle to permit the escape of gas therefrom into the atmosphere and responsive to a deiiciency in pressure of a like amount to admit air from the atmosphere to the receptacle, and means for automatically introducing liquid from the receptacle to form the seal when the liquid Within the receptacle reaches a predetermined level.

In testimony that I claim the foregoing as my own, I have hereto aliixed myr slgnature.

JOHN EDWARD CREWS. 

